clinical pharmacology

TRIMETtiOPRIM RESISTANCE IN FINLAND AFTER FIVE YEARS' USE

A study of the resistance of 1388 urinary bacterial pathogens to plain trimethoprim has confirmed the usefulness of this drug for urinary ltlld. infections. Treatment with trimethoptim alone has a more con¥eruent dosage and a lower incidence of side effect.'I than when it is given in combination with sulphamethoxazole as C()-tnmoxazole, but there has been concern over the possible risks of increasing resistant bacteria. In this study the lowest incidence of resistance was for E. C()1i (J I % for outpatients, 23 % for inpatients) and MicrOCQCCuJ OJ 96 -and ]9 % ), Resistance was intermediate for £rllerobac/er C26 % and ]496), Streptococcus /aecolis (26 % and 29 %)aod Staph. epidermis (2596 and 41 %). A high incidence of resistance was found for Proteus mirabifis (5296 and 76 96 ), Klebsiella (56 96 and 4 I 96) and Pseudomonas (98 96 and 100 96 ). All of 4 Serratia and 4 of 5 Prov;dencia species. isolated were resistant to trimethoprim. 46 strains of 10 different species were also isolated but there were < 8 isolateS of each species. The total iocideoces of resistance to the 954 strains examined from outpatients were 20.396 totrimeilioprim, 16 96 to co­tcimoxazole at a minimum inhibitory concentration ;> 64mg/l and 9.5 % at ::> 5 12mg/l, 2996 to sulphamethoxazole. 28.6 96 to ampicillin and 23.396 to nitrofurantoin. Resistances to inpatient strains were similar for nitrofurantoin and about 10 % higher for the other antibiotics. Considering these results and the established benefits oftrimethoprim ' ... the usefulness of this drug even after five year,' wide use is confirmed.' Huovinen, P. and Toivlnen. ~., Briti5h MediCIJ Journal 280; 72 (I 21an 1980)

12 INPHAAMA 16 Feb 1980 0 156-2703/80/0216-0012 $00.50/0 C ADIS Prest